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Biomedical subjects

D A Murphy

Publications and source records attributed to D A Murphy.

At least 19 recordsLinked to original sources
PubMed1992

Aggression in boys with attention deficit-hyperactivity disorder: methylphenidate effects on naturalistically observed aggression, response to provocation, and social information processing.

High and low-aggressive boys with attention deficit-hyperactivity disorder (ADHD) were compared and the effects of methylphenidate were examined on measures from three domains of aggression: (1) directly observed verbal and nonverbal aggressive behaviors exhibited in the context of a day treatment program, (2) aggressive responding when provoked during a laboratory task, and (3) social information processing patterns exhibited on tasks designed to tap the putative cognitive components of aggression. The high-aggressive (HA) and low-aggressive (LA) subgroups differed significantly on observational measures of aggression and on the laboratory provocation task, but the HA group showed more deviant cognitions on only one of the numerous measures of social information processing. Regarding medication effects on the direct observation measures, methylphenidate decreased aggression for both subgroups. On the laboratory provocation task, methylphenidate had only minimal effects. Significant drug effects were obtained on only two recall social information processing measures.

Aggression↗
PubMed1992

Human cardiac nerve stimulation.

Cardiovascular responses were elicited in 12 patients undergoing cardiac operations when cardiopulmonary neural elements between the aortic root and pulmonary artery or in the right atrial ganglionated plexus were stimulated. Heart rate and left ventricular intramyocardial systolic pressure were augmented when cardiopulmonary nerves between the aorta and pulmonary artery were stimulated in 11 of the 12 patients. Right ventricular intramyocardial systolic pressure was augmented in 7 of these 11 patients. Cardiodepressor responses were elicited when the right atrial ganglionated plexus (9 patients) or a cardiopulmonary nerve (2 patients) was stimulated. These results demonstrate that electrical stimulation of the human extrinsic and intrinsic cardiac nervous systems can alter cardiodynamics, different responses being elicited when different neural structures are stimulated. These data are in accord with those obtained from canine experiments and suggest that the human extrinsic and intrinsic cardiac nervous system contains functionally similar neural elements to those found in other mammals.

Autonomic Nervous System↗
PubMed1992

Accessory atrioventricular node and bundle: a cause of antidromic reentry tachycardia.

Two patients are described with antidromic reentry tachycardia successfully treated by interruption of an anterior septal accessory atrioventricular node and bundle. This anomalous connection resembles an atrioventricular conduction sling seen in complex congenital heart malformations. It has atrioventricular node-like properties, is located in the anterior septal area, will only conduct antegrade, and has an insulated connection to the right bundle branch. Rather than nodoventricular, nodofascicular, atriofascicular, or Mahaim, a more appropriate label for the connection is accessory atrioventricular node and bundle.

Adult↗
PubMed1992

Psychological interventions with AIDS and HIV: prevention and treatment.

In the decade since acquired immune deficiency syndrome (AIDS) was first diagnosed, behavioral research has focused intensively on risk reduction change processes and, to a lesser extent, on mental health needs of persons with human immunodeficiency virus (HIV) conditions. Although research to date has yielded important findings for primary prevention efforts and has identified some psychological dimensions relevant to mental health interventions, there is a pressing need for much more systematic intervention outcome research in both the prevention/behavior change and emotional coping areas. Progress in these areas will be facilitated by better linkage of intervention approaches to behavioral theory; identification of intervention elements that produce HIV risk behavior change; evaluated field-testing of promising intervention models; continued focus on populations that remain at risk (such as gay men and injection drug users); and expansion of prevention efforts to urban, poor, and minority populations increasingly threatened as AIDS/HIV enters a "second wave." Although AIDS is still a relatively new problem, existing behavioral medicine conceptual models and intervention strategies can be adapted to meet the enormous challenges created by AIDS and HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Anxiolytic-like actions of anpirtoline in a mouse light-dark aversion paradigm.

The anxiolytic-like potential of anpirtoline was assessed in a mouse light/dark aversion test. Anpirtoline (1.0 ng kg(-1)-1.0 micrograms kg-1 i.p.) reduced the aversive responding of mice. This was detected as an increase in the latency to locate the non-aversive compartment and by decreases in the percentage of the time spent in the dark compartment, and the numbers of rears and line crossings in the dark compartment. In radioligand binding studies anpirtoline displayed submicromolar affinity for 5-HT1A, 5-HT1B and 5-HT3 receptor recognition sites (Ki = 151, 28 and 30 nM, respectively) and more modest affinity for 5-HT2 receptor recognition sites (Ki = 1.48 microM). It is concluded that anpirtoline has a unique spectrum of affinity for 5-HT receptor subtypes, its interaction with which may account for its anxiolytic-like activity.

Animals↗
PubMed1992

AIDS/HIV risk behavior among the chronic mentally ill.

OBJECTIVE: There is growing concern that chronic mentally ill adults living in the community have a high risk for HIV infection. The purpose of this study was to identify risk knowledge, high-risk behaviors, and risk-related encounters of chronic psychiatric outpatients. METHOD: Detailed information on high-risk behaviors and risk-related situations during the past 12 months was collected from 60 outpatients appearing for regular visits at inner-city community mental health clinics. RESULTS: Of the 60 outpatients, 37 (62%) had been sexually active during the past year, and 42% of the men and 19% of the women reported multiple sexual contacts and infrequent use of condoms during intercourse. Assessments of the patients' knowledge of AIDS risks revealed substantial deficits in their practical understanding of AIDS and risk reduction measures. Although use of intravenous drugs was uncommon in this group, many subjects reported histories of 1) trading sex for money, drugs, or a place to stay, 2) coercion to engage in unwanted sex, 3) causal sexual encounters, and 4) sexual activity after use of drugs or intoxicants. Twenty percent of the subjects had met their sexual partners on the streets, in parks, or in other public places. One-third had been treated for sexually transmitted diseases other than AIDS. CONCLUSIONS: These findings underscore the need for AIDS risk assessment, counseling, and prevention programs for the chronic mentally ill.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Mycobacterium avium-intracellulare endocarditis causing rupture: replacement and repair with aortic homograft.

Aortic valve endocarditis with extension to the tricuspid annulus and ventricular septum in an intravenous drug abuser - with Mycobacterium avium-intracellulare identified as the offending organism - forms the basis of this report. The aortic root and ventricular septal defect were successfully repaired using an aortic cryopreserved homograft. This case is of particular interest because M avium-intracellulare has not been recognized as a cause of endocarditis. The incidence of atypical organisms as a cause of endocarditis may increase in the future because of the rise of drug abuse and the acquired immune deficiency syndrome in North America.

Adult↗
PubMed1992

Continuous warm blood cardioplegia preserves cardiac autonomic function.

We studied in anesthetized dogs, the effects of cardiopulmonary bypass with normothermic whole blood, crossclamping of the aortic root, and continuous warm blood cardioplegia on the ability of the efferent sympathetic nervous system to augment the heart and that of the efferent parasympathetic nervous system to depress the heart. In control states, heart rate, atrial force of contraction, and right and left ventricular wall systolic pressures were augmented by stimulation of the intrathoracic efferent sympathetic nervous system and by administration of isoproterenol into the systemic circulation. After 1 hour of normothermic cardiopulmonary bypass that utilized aortic crossclamping and continuous perfusion of the coronary arteries with normothermic blood (20 mEq/L potassium), cardiac-augmenting effects induced by the efferent sympathetic nervous system and by isoproterenol were similar. Depressive responses elicited by the efferent parasympathetic nervous system were also unaffected by these procedures. Continuous warm blood cardioplegia does not result in impairment of the efferent sympathetic nervous system regulating the heart.

Animals↗
PubMed1992

Acquired immunodeficiency syndrome/human immunodeficiency virus risk behavior among gay men in small cities. Findings of a 16-city national sample.

BACKGROUND: Most research on acquired immunodeficiency syndrome has been conducted in several of the country's largest cities, and little is known about the current level of human immunodeficiency virus risk taking among gay men in other geographical areas. The purpose of this study was to determine the frequency of risk behavior practices among gay men in smaller communities. METHOD: A large sample of men who patronized gay bars in 16 small and moderate-size cities drawn from six states in four different regions of the country was surveyed to determine the frequency of high-risk behavior and factors influencing risk taking. Eighty-five percent of men in all cities' bars completed all survey measures. The community samples were 1991 men; mean age, 31.3 years; mean education, 10.6 years; 90% were white and 10% were of other ethnicities. All participants provided detailed information on their sexual behavior practices over the preceding 2 months and completed measures assessing their perceived peer norms concerning safer sex practices and risk avoidance, intentions to avoid risk, personal risk estimation, acquired immunodeficiency syndrome risk knowledge, perceived threat of acquired immunodeficiency syndrome/human immunodeficiency virus, and serostatus testing history. RESULTS: High-risk patterns were still common among gay men in these smaller cities; nearly one third of all men had engaged in unprotected anal intercourse an average of eight times in the past 2 months, usually outside monogamous relationships. High-risk behavior was most strongly associated with beliefs that safer sex practices would not be well accepted by peers, weak intentions to use condoms, underestimation of personal vulnerability to the acquired immunodeficiency syndrome, younger age, and higher levels of overall sexual activity. Nine percent of men tested said they were seropositive. CONCLUSIONS: Growing human immunodeficiency virus prevalence and continued high rates of risk behavior indicate that a new "front line" for human immunodeficiency virus prevention among homosexually active men has shifted to the country's smaller cities. Community prevention efforts in these areas are urgently needed to avert sharp increases in future human immunodeficiency virus infections in this population.

Acquired Immunodeficiency Syndrome↗
PubMed1992

A needs assessment survey of HIV-infected patients.

Few studies have surveyed HIV-infected patients to determine how adequately medical, legal, psychological, social service, and financial needs are being met through current treatment services. Fifty HIV-infected men seen at a county medical facility were surveyed to determine which of 17 needs were being met and the importance rating attributed to those needs. Five needs were reported by more than 30% of the sample as not being met: 1) being able to talk about fears of the future, illness, or death; 2) being occupied and having things to do; 3) having up-to-date information about HIV; 4) having someone to help them with their feelings of depression, helplessness, anxiety, or anger; and 5) help for the patient's family. Three of these five needs involve better access to psychological services. Although patients felt they had knowledgeable medical staff and good health care, they wanted more up-to-date information on HIV treatment.

Adult↗
PubMed1992

Influences of cardiopulmonary bypass, temperature, cardioplegia, and topical hypothermia on cardiac innervation.

The effects of normothermic and hypothermic cardiopulmonary bypass, crossclamping of the aortic root, cold cardioplegia, as well as epicardial application of iced slush, on the efficacy of the efferent sympathetic nervous system to augment the heart and the efferent parasympathetic nervous system to depress the heart were studied in anesthetized dogs. Cardiac rate and force are augmented by stimulation of the intrathoracic efferent sympathetic nervous system and reduced by stimulation of the intrathoracic efferent parasympathetic nervous system. After cardiopulmonary bypass, which included systemic and topical hypothermia, aortic crossclamping, and crystalloid cardioplegia, the augmentor effects of the efferent sympathetic nervous system were obtunded whereas the depressor effects exerted by the efferent parasympathetic nervous system were not. Direct cardiac myocyte augmentor responses induced by isoproterenol were unaffected by these interventions. Normothermic cardiopulmonary bypass, hypothermic cardiopulmonary bypass, crossclamping of the aorta, or cold cardioplegia did not result in blunting of the efferent sympathetic cardiac nervous system. Significant blunting of cardiac augmentation induced by the efferent sympathetic nervous system occurred after topical application of iced slush alone. These data demonstrate that blunting of the efferent sympathetic, but not parasympathetic, innervation of the heart occurs after cardiopulmonary bypass, which presumably is primarily due to altering the function of subepicardial efferent sympathetic axons by topical hypothermia and not due to altered cardiac myocyte function. These data imply that after cardiopulmonary bypass involving the procedures described, the ability of the efferent sympathetic nervous system to support cardiac rate and force is transiently impaired.

Animals↗
PubMed1991

Effects of background anger, provocation, and methylphenidate on emotional arousal and aggressive responding in attention-deficit hyperactivity disordered boys with and without concurrent aggressiveness.

We investigated the effects of background anger, provocation, and methylphenidate on emotional, physiological, and behavioral responding in children with attention-deficit hyperactivity disorder (ADHD) with and without concurrent aggression. Our study revealed that ADHD boys showed more emotional and physiological distress when exposed to an interaction in which an administrator chastised each boy's favorite counselor, compared to a friendly interaction between the two adults. The background anger manipulation did not affect the aggressive behavior of the boys against an opponent in an aggressive game. High-aggressive (HA) ADHD boys were more likely to respond to provocation with aggression than low-aggressive (LA) ADHD boys, but only LA boys showed increased physiological reactivity with increasing provocation. Methylphenidate resulted in increased heart rates under all conditions and did not interact with any of the other findings.

Adult↗
PubMed1991

Cognitive enhancing actions of PD123177 detected in a mouse habituation paradigm.

The anxiolytic-like and cognitive enhancing potential of PD123177, a non-peptide with selectivity for the angiotensin II-2 receptor recognition site, was assessed in a mouse light/dark aversion test and habituation test, respectively. PD123177 (0.01 ng kg-1 to 1.0 mg kg-1 i.p.) failed to alter the behavioural repertoire of animals in the light/dark aversion test. In contrast, daily administration of PD123177 (10.0 ng kg-1 i.p. b.d.) enhanced the performance of mice in a habituation test. In addition, PD123177 overcame the cognitive impairment induced by the administration of scopolamine (0.25 mg kg-1 i.p.). Such findings indicate for the first time a functional role for the angiotension II-2 receptor and further implicate the angiotensin system in the modulation of cognitive processes.

Angiotensin II↗
PubMed1991

Atrioventricular canal defects: results of repair in the current era.

Between December 1986 and December 1990, 37 consecutive patients underwent repair of complete atrioventricular (AV) canal with the two-patch technique. Mean age at repair was 22 months and 51% were less than 1 year of age. Eighteen (48.6%) had undergone previous palliative operations. Two operative deaths (5.4%) occurred and another patient died in-hospital for an early mortality of 8.1%. One late death (2.9%) has occurred from a respiratory infection. Actuarial survival is 87.7% at 3 years. Small size (p less than 0.05), unbalanced ventricular size (p less than 0.05), New York Heart Association (NYHA) Class IV (p less than 0.05), and severe preoperative AV valve insufficiency (p less than 0.05) were significant preoperative risk factors for death. Five survivors (14.7%) required reoperation for severe AV valve insufficiency (two) or patch leaks (three). The risk for reoperation was increased in non-Down's patients (p less than 0.02). All survivors are in NYHA Class I (93%) or II (7%). The risk for early AV valve insufficiency was increased in patients who did not have the cleft sutured (p less than 0.05), and in those with unbalanced ventricles (p less than 0.01). Risk of late AV valve insufficiency was increased only by small size (p less than 0.02). Previous pulmonary artery banding did not increase the risk of repair or of postoperative AV valve insufficiency. Complete AV canal can be repaired with low mortality. Pulmonary artery banding may still have a role to play in the very small (4-5 kg) infant in refractory heart failure.

Aortic Valve Insufficiency↗
PubMed1991

Idiopathic dilatation of the aorta with dissection in a family without Marfan syndrome.

Dissection of the aorta is very rare in children, but classically occurs in the presence of Marfan syndrome or other connective tissue disorder. We present a case of spontaneous dissection in a 12-year-old boy whose half brother has an idiopathic dilated aorta and whose mother has also required surgery for dissection of a dilated aorta. No features of connective tissue disorder were present in any family member.

Adult↗
PubMed1990

Modification of supraventricular tachyarrhythmias by stimulating atrial neurons.

The effects of stimulating the right atrial ventral ganglionated plexus on ventricular performance during atrial tachycardia was studied in 8 lightly sedated (pentobarbital, 2.5 mg/kg intravenously) dogs with sterile pericarditis. Atrial arrhythmias were induced by electrical stimulation (10 V, 4 ms, 100 Hz) of the right atrium through previously inserted temporary bipolar pacemaker wires. Various types of supraventricular tachycardias were produced. Atrial fibrillation was produced in 3 dogs, atrial tachycardia in all 8 dogs, different atrioventricular nodal ectopic rhythms in 6 dogs, and atrial flutter in 1 dog. These arrhythmias were associated with irregular ventricular contractions that resulted in low ventricular pressures during many cardiac cycles such that low or no aortic pressure was generated. Right atrial ventral ganglionated plexus stimulation induced slowing of ventricular rate so that every ventricular contraction resulted in aortic pressure generation, thus increasing mean aortic pressure. Responses elicited by atrial ganglionated plexus stimulation were eliminated after atropine administration. We conclude that electrical stimulation of the right atrial ventral ganglionated plexus results in slowing of ventricular contractile rate during supraventricular tachycardia, presumably by activating efferent vagal neuronal elements, thereby improving ventricular performance. If applicable in humans, this technique may be of use in management of postoperative atrial arrhythmias after cardiac operations.

Animals↗